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A125824
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Denominator of n!/3^n.
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1
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1, 3, 9, 9, 27, 81, 81, 243, 729, 243, 729, 2187, 2187, 6561, 19683, 19683, 59049, 177147, 59049, 177147, 531441, 531441, 1594323, 4782969, 4782969, 14348907, 43046721, 4782969, 14348907, 43046721, 43046721, 129140163, 387420489
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(0)=1, a(3n+2)=3^(n+2)*a(n), a(3n+1)=3^(n+1)*a(n), a(3n)=3^n*a(n) ; a(n)=3^A089792(n)
a(n)=denominator((1/(2*pi))*int(exp(i*3*t)(-((pi-t)/i)^n),t,0,2*pi)), i=sqrt(-1); a(n)=3^A089792(n); - Paul Barry (pbarry(AT)wit.ie), Apr 02 2007
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PROG
| (PARI) a(n)=denominator(n!/3^n)
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CROSSREFS
| Sequence in context: A206700 A162349 A072404 * A203558 A038227 A080292
Adjacent sequences: A125821 A125822 A125823 * A125825 A125826 A125827
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KEYWORD
| nonn,frac
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 06 2007
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